I did it, manually, using this set of commands (some of them slightly modified). Then, I will update the fw on the SD card, and by executing almost all the commands in the thread, except for partitioning and copying the /data partition to the ssd. And it seems to be working well so far.
PS: in fstab, instead of /dev/root , /dev/sda1 and /dev/sda4 , I used PARTUUID=ID_ROOT_PART, PARTUUID=ID_BOOT_PART and PARTUUID=ID_DATA_PART, which as long as we don’t format the ssd will be the same every time.
It’s something like 15 minutes of typing commands on ssh, so I don’t think it’s a problem.
Cheers